Downhole smart completion multi-access tools for acid stimulation

ABSTRACT

A downhole access tool for accessing a lateral branch of a wellbore includes a tool body, a sliding sleeve, and a deflector device including a deflector plate and a deflector actuator operatively coupled to the deflector plate. A central conduit extends axially through the downhole access tool. The sliding sleeve is slidable relative to the tool body in an axial direction between a closed position and an open position. In the closed position, the sliding sleeve restricts access through the opening. In the open position, the sliding sleeve permits access through the opening. The deflector actuator transitions the deflector plate between a deflection position and a passthrough position. In the deflection position, the deflector plate deflects tooling radially outward towards the opening. In the passthrough position, the deflector plate allows access axially through the central conduit.

TECHNICAL FIELD

The present specification generally relates to natural resource well drilling and hydrocarbon production from subterranean formations, in particular, to apparatus and systems for well completion of natural resource wells.

BACKGROUND

Production of hydrocarbons from a subterranean formation generally includes drilling at least one wellbore into the subterranean formation. The wellbore forms a pathway capable of permitting both fluids and apparatus to traverse between the surface and the subterranean formations. Besides defining the void volume of the wellbore, the wellbore wall also acts as the interface through which fluid can transition between the formations through which the wellbore traverses and the interior of the wellbore. Hydrocarbon producing wellbores extend subsurface and intersect various subterranean formations where hydrocarbons are trapped. Well drilling techniques can include forming multilateral wells that include lateral branches or laterals that extend laterally outward from a central wellbore, which may be referred to as the “motherbore.”

Each lateral branch generally extends into a different part of the subterranean formation. Hydrocarbon production may slow from the lateral branches after producing for a certain period. Lateral branches may be stimulated, for example, by using acid stimulation, to increase the production of hydrocarbons after production has slowed. For this purpose, downhole access tools may be installed in the motherbore for access to the lateral branches.

SUMMARY

Downhole access tools installed in multi-lateral branches during wellbore completion may include deflector devices for redirecting a casing string from the motherbore to the lateral branch. However, lateral branches require additional access tools for selectively opening and closing the lateral branch. Additional access tools require additional operator intervention and installation.

Accordingly, there is an ongoing need for downhole access tools and methods of using downhole access tools for accessing and directing tooling to lateral branches of a wellbore. The access tools of the present disclosure include a tool body having an opening that can be positioned to align with a lateral branch of a wellbore. The multi-access tool further includes a sliding sleeve and a deflector device having a deflector plate and a deflector actuator for operating the deflector plate. The sliding sleeve may be translatable axially to expose or cover the opening in the tool body to allow or restrict access to the lateral branch. The deflector device may be operable to move the deflector plate between a passthrough position and a deflection position. The access tool may be positioned within the wellbore so that the opening in the tool body is aligned with the lateral branch. When the access tool is in a diversion condition, the sliding sleeve may be in an open position to provide access to the lateral branch, and the deflector plate may be in a deflection position to cause tooling extended down into the wellbore to be deflected by the deflector plate, through the opening in the tool body, and into the lateral branch. When the access tool is in a passthrough condition, the sliding sleeve may be in a closed position to restrict access to the lateral branch, and the deflector plate may be in the passthrough position so that tooling extended downhole will pass axially through the access tool and continue into the deeper sections of the motherbore. The access tool may be transitioned between the diversion condition and the passthrough condition without removing the access tool or any part thereof from the wellbore. Thus, the access tool may be used to control deployment of tooling between a lateral branch and the motherbore without having to remove and reinstall various diverting devices in the wellbore.

According to one aspect of the present disclosure, a downhole access tool for providing access to a lateral branch of a wellbore includes: a tool body including a cylindrical wall having an opening extending radially through the cylindrical wall; a sliding sleeve disposed within the tool body; and a deflector device including a deflector plate coupled to the tool body, the sliding sleeve, or both and a deflector actuator operatively coupled to the deflector plate. The sliding sleeve, the tool body, or both define a central conduit extending axially through the downhole access tool. The sliding sleeve is slidable relative to the tool body in an axial direction between a closed position and an open position. In the closed position, the sliding sleeve may restrict access through the opening in the tool body and, in the open position, the sliding sleeve may permit access through the opening in the tool body. The deflector actuator is operable to transition the deflector plate between a deflection position and a passthrough position. In the deflection position, the deflector plate may restrict access axially through the central conduit and may deflect tooling radially outward towards the opening in the tool body. In the passthrough position, the deflector plate may allow access axially through the central conduit.

According to a second aspect of the present disclosure, a method for treating a subterranean formation comprises installing the downhole access tool of the first aspect in a wellbore at a junction of a lateral branch with the wellbore. The downhole access tool may be oriented in the wellbore so that the opening in the tool body is aligned with the lateral branch. The method may further include transitioning the downhole access tool to a diversion state where the sliding sleeve is in the open position and the deflector plate is in the deflection position and inserting a coiled tubing into the wellbore. The deflector plate of the deflector device may deflect the coiled tubing radially outward through the opening in the tool body and into the lateral branch. The method may further include injecting a treatment fluid from the coiled tubing into the subterranean formation in fluid communication with the lateral branch.

Additional features and advantages of the technology described in this disclosure will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the technology as described in this disclosure, including the detailed description which follows, the claims, as well as the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

FIG. 1 schematically depicts a side cross-sectional view of a multilateral wellbore comprising a downhole access tool according to one or more embodiments shown and described in this disclosure;

FIG. 2A schematically depicts a top view in partial cross-section of the downhole access tool depicted in FIG. 1 in a diversion state, according to one or more embodiments shown and described in this disclosure;

FIG. 2B schematically depicts a top view in partial cross-section of the downhole access tool depicted in FIG. 1 in a passthrough state, according to one or more embodiments shown and described in this disclosure;

FIG. 3A schematically depicts a side cross-sectional view of the downhole access tool depicted in FIG. 1 in the passthrough state, according to one or more embodiments shown and described in this disclosure;

FIG. 3B schematically depicts a side cross-sectional view of another embodiment of a downhole access tool in the passthrough state, according to one or more embodiments shown and described in this disclosure;

FIG. 4 schematically depicts a side cross-sectional view of the downhole access tool depicted in FIG. 1 in the diversion state, according to one or more embodiments shown and described in this disclosure;

FIG. 5 schematically depicts communication between various modules of the downhole access tool, according to one or more embodiments shown and described herein; and

FIG. 6 schematically depicts a flow diagram of a method of operating the downhole access tool, according to one or more embodiments shown and described herein.

Reference will now be made in greater detail to various embodiments, some embodiments of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts.

DETAILED DESCRIPTION

The present disclosure is directed to downhole access tools and methods for accessing one or more lateral branches of a multilateral wellbore using the downhole access tool. One embodiment of a downhole access tool according to the present disclosure includes a tool body including a cylindrical wall having an opening extending radially through the cylindrical wall. The downhole access tool further includes a sliding sleeve disposed within the tool body and a deflector device that may comprise a deflector plate coupled to the tool body, the sliding sleeve, or both and a deflector actuator operatively coupled to the deflector plate. The sliding sleeve, the tool body, or both may define a central conduit extending axially through the downhole access tool. The sliding sleeve may be slidable relative to the tool body in an axial direction between a closed position and an open position. In the closed position, the sliding sleeve may restrict access through the opening in the tool body. In the open position, the sliding sleeve may permit access through the opening in the tool body. The deflector actuator may be operable to transition the deflector plate between a deflection position and a passthrough position. In the deflection position, the deflector plate may restrict access axially through the central conduit and may deflect tooling radially outward towards the opening in the tool body. In the passthrough position, the deflector plate may allow access axially through the central conduit.

The downhole access tool may be used to selectively permit access to the various lateral branches with a single actuation. The single actuation may control both the deflector device and the sliding sleeve, allowing the deflector device to redirect a drill string, coiled tubing, or other wellbore tooling into the adjacent lateral branch and actuating the sliding sleeve in an axial direction to permit access to the opening.

As used throughout the present disclosure, the term “hydrocarbon-bearing formation” refers to a subterranean geologic region containing hydrocarbons, such as crude oil, hydrocarbon gases, or both, which may be extracted from the subterranean geologic region. The terms “subterranean formation” or just “formation” may refer to a subterranean geologic region that contains hydrocarbons or a subterranean geologic region proximate to a hydrocarbon-bearing formation, such as a subterranean geologic region to be treated for purposes of enhanced oil recovery or reduction of water production.

As used throughout the present disclosure, the terms “motherbore” and “central bore” may be used interchangeably and may refer to the main trunk of a wellbore extending from the surface downward to at least one subterranean formation.

As used throughout the present disclosure, the term “lateral branch” refers to a secondary bore in fluid communication with the central bore or motherbore and extending from the central bore laterally into a subterranean formation. The central bore may connect each lateral branch to the surface.

As used in the present disclosure, the term “uphole” refers to a direction in a wellbore that is towards the surface, such as in the +Z direction of the coordinate axis in FIG. 1 . For example, a first component that is uphole relative to a second component is positioned closer to the surface of the wellbore relative to the second component.

As used in the present disclosure, the term “downhole” refers to a direction further into the formation and away from the surface. For example, a first component that is downhole relative to a second component is positioned farther away from the surface of the wellbore relative to the second component.

As used throughout the present disclosure, the term “fluid” can include liquids, gases, or both and may include solids in combination with the liquids, gases, or both, such as but not limited to suspended solids in the wellbore fluids, entrained particles in gas produced from the wellbore, drilling fluids comprising weighting agents, or other mixed phase suspensions, slurries and other fluids.

As used in the present disclosure, components coupled “directly” to one another may refer to a first component being coupled to a second component without a third component intervening between the first and second components.

Referring now to FIG. 1 , a wellbore 100 for producing hydrocarbons from one or more hydrocarbon-bearing subterranean formations 104 is schematically depicted. The wellbore 100 extends from a surface 102 downward (i.e., in the −Z direction of the coordinate axis in FIG. 1 ) to or through one or more hydrocarbon-bearing subterranean formations 104. The wellbore 100 may include a central bore 110 (motherbore). The wellbore 100 may also include one or a plurality of lateral branches 112. Each lateral branch 112 may extend into a different hydrocarbon-bearing subterranean formation 104, such as hydrocarbon-bearing subterranean formations 104 at different depths or into different regions of a single hydrocarbon-bearing subterranean formation 104. In embodiments, the central bore 110 may be a non-vertical wellbore such as a horizontal wellbore or angled wellbore. For non-vertical central bores 110, the lateral branches 112 may extend at least partially in the vertical direction (e.g., +/−Z direction of the coordinate axis in FIG. 1 ) from the central bore 110 into the hydrocarbon-bearing subterranean formation 104. The central bore 110 can be lined with one or more casings 114, such as production tubing, which may be cemented in place in the central bore 110. The lateral branches 112 may be lined or unlined. When lined, the lateral branches 112 may be perforated in one or more locations to allow hydrocarbon-containing fluids to flow from the hydrocarbon-bearing subterranean formation 104 into the lateral branch 112.

Referring still to FIG. 1 , the present disclosure is directed to downhole access tools 120 operable to control access of wellbore tooling to lateral branches 112 of the wellbore 100. The downhole access tools 120 of the present disclosure may include a tool body 122, a sliding sleeve 140, a deflector device 150, and a biasing mechanism 170. The tool body 122 may include a cylindrical wall 124 and a wellbore anchor 132. The cylindrical wall 124 may include an uphole end 125 and a downhole end 127. The cylindrical wall 124 may be a hollow cylinder having an outer surface 126 and an inner surface 128. The inner surface 128 may define a central conduit 130 extending axially (e.g., in the +/−Z direction) through the cylindrical wall 124. The cylindrical wall 124 may include a tab 139. The tab 139 may extend radially inward from the inner surface 128 of the cylindrical wall 124. The tab 139 may be positioned below the sliding sleeve 140. However, in embodiments, the tab 139 may be positioned above the sliding sleeve 140.

Referring still to FIG. 1 , the cylindrical wall 124 may include an opening 134 extending radially through the cylindrical wall 124. The opening 134 may circumscribe a radial line 133 extending perpendicularly from a center axis 158 of the downhole access tool 120. The opening 134 may be in fluid communication with the central conduit 130 defined by the cylindrical wall 124 to allow fluids to pass through the cylindrical wall 124 between the lateral branch 112 and the central conduit 130 or allow wellbore tooling to pass from the central conduit 130 into the lateral branch 112. The opening 134 may have any cross-sectional shape, such as but not limited to circular, triangular, rectangular, or the like. The downhole access tool 120 may be oriented in the central bore 110 so that the opening 134 is aligned with the lateral branch 112. In embodiments, the downhole access tool 120 may be oriented within the central bore 110 so that the radial line 133 circumscribed by the opening 134 passes through the inlet 105 of the lateral branch 112.

The wellbore anchor 132 may extend radially outward from the tool body 122. The wellbore anchor 132 may be operable to rigidly couple the tool body 122 to the casing 114 within the central bore 110 or directly to the wellbore wall. The wellbore anchor 132 may extend from a portion of the tool body 122 and be disposed proximate to the downhole end 127 of the tool body 122. The wellbore anchor 132 may be operable to expand from the tool body 122 and engage with the casing 114 of the central bore 110 to at least prevent downhole movement of the downhole access tool 120 during movement of the sliding sleeve 140 and/or the deflector plate 152. The wellbore anchor 132 may be integrated with the tool body 122 and may include one or a plurality of wellbore anchors 132 coupled to the outer surface 126 of the tool body 122. The wellbore anchors 132 may be disposed in or on the outer surface 126 of the tool body 122. In some embodiments, the wellbore anchors 132 may be axially positioned uphole relative to the opening 134. The wellbore anchors 132 may be expandable or translatable radially outward from the tool body 122 to engage with the casing 114 of the central bore 110. In embodiments, the wellbore anchors 132 may pivot outward when activated. The wellbore anchors 132 may by hydraulically activated. When engaged, the wellbore anchors 132 may prevent downhole movement of the downhole access tool 120 during movement of the sliding sleeve 140 and/or the deflector plate 152. In embodiments, the wellbore anchors 132 may reduce or prevent uphole and/or downhole movement of the downhole access tool 120. In embodiments, the wellbore anchor 132 may be separate from the tool body 122.

Referring still to FIG. 1 , the sliding sleeve 140 may be a hollow cylindrical sleeve having an outer sleeve surface 142, an inner sleeve surface 144, an uphole end 148, and a downhole end 149, which may be opposite the uphole end 148. The inner sleeve surface 144 may define a cylindrical cavity 145 extending axially (e.g., in the +/−Z direction of FIG. 1 ) through the sliding sleeve 140. The sliding sleeve 140 may be disposed within the tool body 122. The sliding sleeve 140 may be movably coupled to the tool body 122 such that the sliding sleeve 140 is slidable relative to the tool body 122 in the axial direction (e.g., in the +/−Z direction of FIG. 1 ). The central conduit 130 of the tool body 122 and the cylindrical cavity 145 of the sliding sleeve 140 may cooperate to define a cavity that extends axially through the downhole access tool 120.

The sliding sleeve 140 may move between an open position and a closed position. In the closed position, the outer sleeve surface 142 of the sliding sleeve 140 may be positioned within the cylindrical wall 124 of the tool body 122 at the opening 134 to extend across the opening 134, restricting access from the central conduit 130 through the opening 134 and into the lateral branch 112. In the open position, the sliding sleeve 140 may be translated away from the opening 134 in the axial direction (e.g., in the +/−Z direction) to permit access to the lateral branch 112 through the opening 134. In the open position, the sliding sleeve 140 may be positioned above or below the opening 134. The sliding sleeve 140 may include a sliding sleeve actuator 146 operatively coupled to the sliding sleeve 140. The sliding sleeve actuator 146 may be configured to translate the sliding sleeve 140 axially between the open position and the closed position. The sliding sleeve actuator 146 may be a pneumatic actuator, a hydraulic actuator, an electric actuator, a linear actuator, a rotary actuator, or the like.

Referring to FIGS. 1, 2A, and 2B, the deflector device 150 may include a deflector plate 152, and a deflector actuator 154. Referring to FIGS. 2A and 2B, the deflector plate 152 may include a deflecting surface 156. The deflector plate 152 may be pivotally coupled to the inner surface 128 of the cylindrical wall 124 to allow the deflector plate 152 to pivot between a deflection position (FIG. 2A) and a passthrough position (FIG. 2B). In embodiments, the deflector plate 152 may be pivotally coupled to the cylindrical wall 124 by a pin 162 at a pivot point 160. In embodiments, the deflector plate 152 and deflecting surface 156 may be substantially flat. In embodiments, the deflector plate 152 and deflecting surface 156 may be curved, such that the deflecting surface 156 of the deflector plate 152 mirrors a contour of the inner surface 128 of the cylindrical wall 124. When the deflector plate 152 is curved, the deflector plate 152 may lay against the inner surface 128 in the passthrough position and not protrude inward toward the center axis 158 of the downhole access tool 120 significantly more than the thickness of the deflector plate 152. Thus, in the passthrough position, the deflector plate 152 does not impede actuation of the sliding sleeve 140 or impede travel of tooling installed axially through the downhole access tool 120.

Referring again to FIG. 1 , the deflector actuator 154 may be operatively coupled to the deflector plate 152. The deflector actuator 154 may be rigidly coupled to the tool body 122 or to the sliding sleeve 140. The deflector actuator 154 may be operable to transition the deflector plate 152 between the deflection position and the passthrough position. In embodiments, the deflector actuator 154 may be operable to rotate the deflector plate 152 about the pivot point 160 to translate the deflector plate 152 between the passthrough position (FIG. 1 ) and the deflection position (FIG. 4 ). The deflector actuator 154 may be a pneumatic actuator, a hydraulic actuator, an electric actuator, a linear actuator, a rotary actuator, or the like. Referring to FIG. 2A, a top view of the deflector plate 152 in the deflection position is shown, where the deflector plate 152 extends across a substantial portion of the cross sectional area of the central conduit 130. Referring now to FIG. 2B, the deflector plate 152 is shown in the passthrough position in which the deflector plate 152 may be pivoted against the inner surface of the sliding sleeve 140 so that the central conduit 130 is clear of obstruction from the deflector plate 152.

Referring to FIGS. 1 and 2B, when the deflector plate 152 is in the passthrough position, the deflecting surface 156 of the deflector plate 152 may not intersect the center axis 158 of the downhole access tool 120 to allow access axially through the central conduit 130. Specifically, when the deflector plate 152 is in the passthrough position, coiled tubing 190, a drill string, or other wellbore tooling may pass along the central bore 110 through the central conduit 130 of the tool body 122 to a position in the central bore 110 downhole of the downhole access tool 120. When the deflector plate 152 is in the passthrough position, the deflecting surface 156 does not provide any impedance to wellbore tooling inserted into the wellbore and extended through the downhole access tool 120. In embodiments, when the deflector plate 152 is in the passthrough position, the deflecting surface 156 of the deflector plate 152 may be parallel to the center axis 158 of the downhole access tool 120. In the passthrough position, the deflector plate 152 may be recessed into the tool body 122 such that the deflecting surface 156 does not form a step with the inner surface 128 of the tool body 122.

Referring again to FIG. 1 , in embodiments, the downhole access tool 120 may further include the biasing mechanism 170. The biasing mechanism 170 may include a spring piston 172. The spring piston 172 may be coupled to the tab 139 of the tool body 122. The spring piston 172 may extend axially from the tab 139 to be in contact with the sliding sleeve 140. When the tab 139 is positioned below the sliding sleeve 140, the spring piston 172 may extend from the tab 139 to contact the downhole end 149 of the sliding sleeve 140. Referring now to FIG. 3A, when the tab 139 is positioned above the sliding sleeve 140, the spring piston 172 may extend from the tab 139 to contact the uphole end 148 of the sliding sleeve 140. Referring again to FIG. 1 , the spring piston 172 may bias the sliding sleeve 140 from the open position to the closed position. When the sliding sleeve 140 is in the open position, the spring piston 172 may be compressed between the tab 139 and the sliding sleeve 140. The compression from the spring piston 172 may bias the sliding sleeve 140 away from the tab 139 to the closed position.

A hydraulic control line 180 may be operatively coupled to the sliding sleeve actuator 146, the deflector actuator 154, or both to move the downhole access tool 120 between the diversion state and the passthrough state. The hydraulic control line 180 may be operable to actuate the sliding sleeve actuator 146, the deflector actuator 154, or both. Specifically, the hydraulic control line 180 may actuate the sliding sleeve actuator 146 to move the sliding sleeve 140 between the open position and the closed position. Similarly, the hydraulic control line 180 may actuate the deflector actuator 154 to move the deflector plate 152 between the deflection position and the passthrough position. The hydraulic control line 180 may be activated and deactivated by increasing and decreasing a pressure through the hydraulic control line 180. In embodiments, the hydraulic control line 180 may be activated by increasing the pressure in the hydraulic control line 180 and deactivated by decreasing the pressure in the hydraulic control line 180. The hydraulic control line 180 may be coupled to both the sliding sleeve actuator 146 and the deflector actuator 154 to actuate both the sliding sleeve actuator 146 and the deflector actuator 154 when the pressure in the hydraulic control line 180 is increased and decreased.

In embodiments, the sliding sleeve actuator 146, the deflector actuator 154, or both may be electrically powered. In these embodiments, the sliding sleeve actuator 146, the deflector actuator 154, or both may be in electrical communication with an electrical power source. The electrical power source may supply power to the sliding sleeve actuator 146 and the deflector actuator 154 to selectively actuate the sliding sleeve actuator 146 and the deflector actuator 154. In embodiments, the electrical power source may be disposed at the surface and electrically coupled to the sliding sleeve actuator 146, deflector actuator 154, or both with an electrical line extending downhole from the surface 102 to the downhole access tool 120. Controls at the surface may be communicatively coupled to the power source to allow operator control of the downhole access tool 120 from the surface 102.

Referring again to FIG. 3A, the tool body 122 may have a recess 135 extending radially outward into the inner surface 128 of the tool body 122 (e.g., the recess 135 being sunken into the inner surface 128 of the tool body 122). The deflector plate 152 may be pivotally coupled to the tool body 122 at a position where, in the passthrough position, the deflector plate 152 is positioned within the recess 135. Specifically, the pin 162 may be positioned within the recess 135, pivotally coupling the deflector plate 152 to the tool body 122 within the recess 135. In the passthrough position, the deflector plate 152 may be at least partially positioned within the recess 135 such that the sliding sleeve 140 may move between the open position and the closed position without contacting the deflector plate 152 or without the deflector plate 152 impeding movement of the sliding sleeve 140 in any manner.

Referring now to FIG. 3B, in embodiments, the deflector device 150 may be pivotally coupled to the inner sleeve surface 144 of the sliding sleeve 140. The sliding sleeve 140 may have a sleeve recess 136 extending radially outward into the inner sleeve surface 144 of the sliding sleeve 140. The deflector plate 152 may be pivotally coupled to the sliding sleeve 140 at a position where, in the passthrough position, the deflector plate 152 is positioned within the sleeve recess 136. Specifically, the pin 162 may be positioned within the sleeve recess 136, pivotally coupling the deflector plate 152 to the sliding sleeve 140 within the sleeve recess 136. In the passthrough position, the deflector plate 152 may be at least partially or fully positioned within the sleeve recess 136.

Referring now to FIG. 4 , when the deflector plate 152 is in the deflection position, the deflector plate 152 may extend inward into the central conduit 130 so that the deflecting surface 156 of the deflector plate 152 may intersect the center axis 158 of the downhole access tool 120. When the deflector plate 152 is in the deflection position, the deflecting surface 156 of the deflector plate 152 may form an angle α with the center axis 158, where the angle α is greater than zero. When the deflector plate 152 is in the deflection position, the deflector plate 152 may restrict or impede access axially through the central conduit 130.

The downhole access tool 120 may be movable between a diversion state and a passthrough state. In the diversion state, the sliding sleeve 140 is in the open position and the deflector plate 152 is in the deflection position. In the passthrough state, the sliding sleeve 140 is in the closed position and the deflector plate 152 is in the passthrough position.

Referring again to FIG. 4 , when the downhole access tool 120 is in the diversion state, a coiled tubing 190, drill string, or other wellbore tooling inserted into the wellbore 100 may contact and be deflected by the deflecting surface 156 of the deflector plate 152. The coiled tubing 190 or other wellbore tooling may be deflected at an angle oblique to the center axis 158 towards the opening 134 of the tool body 122. Specifically, the deflector plate 152 may deflect the coiled tubing 190 radially outward towards the opening 134 in the tool body 122. The coiled tubing 190 may extend through the opening 134 into the lateral branch 112. When positioned within the lateral branch 112, the coiled tubing 190 may be used to stimulate the hydrocarbon-bearing subterranean formations 104 in the lateral branch 112 to increase the production of hydrocarbons from the lateral branch 112. The coiled tubing 190 may stimulate the lateral branch 112 through acid stimulation, or other known methods. Although described in terms of deflecting coiled tubing 190 into the lateral branch 112, the downhole access tool 120 may also be effective to divert other types of wellbore tooling into the lateral branch 112. Other types of wellbore tooling may include but is not limited to drill strings, wellbore logging equipment, or other devices or equipment.

When the downhole access tool 120 is in the passthrough state, a coiled tubing 190, drill string, or other wellbore tooling inserted into the wellbore may pass through the downhole access tool 120 to access another part of the wellbore, such as downhole sections of the central bore 110 or another lateral branch downhole of the downhole access tool 120. In the passthrough state, the deflector plate 152 is in the passthrough position, such that the deflector plate 152 does not interfere with the coiled tubing 190 passing through the downhole access tool 120. In the passthrough state, the sliding sleeve 140 is in the closed position. With the sliding sleeve 140 in the closed position, the sliding sleeve 140 restricts access to the lateral branch 112. By restricting access to the lateral branch 112, the sliding sleeve 140 may prevent the coiled tubing 190 from inadvertently passing into the lateral branch 112 when passing through the downhole access tool 120.

Referring now to FIG. 5 , the downhole access tool 120 may further include an electronic control unit (ECU) 200 and a communication path 202. The ECU 200 may be communicatively coupled to the hydraulic control lines 180 via the communication path 202 such that the ECU 200 may control operation of the sliding sleeve actuator 146 and the deflector actuator 154 through the hydraulic control lines 180. In embodiments, the ECU 200 may be communicatively coupled to the sliding sleeve actuator 146 and the deflector actuator 154 via the communication path 202 to provide and receive signals from the sliding sleeve actuator 146 and the deflector actuator 154 for direct control of the sliding sleeve actuator 146 and the deflector actuator 154. The communication path 202 may provide data interconnectivity between various modules disposed within the downhole access tool 120. Specifically, each of the modules can operate as a node that may send and/or receive data. In some embodiments, the communication path 202 may include a conductive material that permits the transmission of electrical data signals to and between processors, memories, sensors, and valves, pumps, etc. throughout the downhole access tool 120. In another embodiment, the communication path 202 can be a bus, such as for example a LIN bus, a CAN bus, a VAN bus, and the like. In further embodiments, the communication path 202 may be wireless and/or an optical waveguide. Components that are communicatively coupled may include components capable of exchanging data signals with one another such as, for example, electrical signals via conductive medium, electromagnetic signals via air, optical signals via optical waveguides, and the like.

The ECU 200 may be configured to selectively operate components of the downhole access tool 120. For example, the ECU 200 may control the sliding sleeve actuator 146 to move the sliding sleeve 140 between the open position and the closed position, and the deflector actuator 154 to move the deflector plate 152 between the deflection position and the passthrough position.

The ECU 200 may include one or more processors 204 and one or more memory modules 206. The one or more processors 204 may include any device capable of executing computer-readable executable instructions stored on a non-transitory computer-readable medium. Accordingly, each processor may include a controller, an integrated circuit, a microchip, a computer, and/or any other computing device. It is noted that the one or more processors 204 may reside within the downhole access tool 120 and/or external to the downhole access tool 120.

The one or more memory modules 206 are communicatively coupled to the one or more processors 204 over the communication path 202. The one or more memory modules 206 may be configured as volatile and/or nonvolatile memory and, as such, may include random access memory (including SRAM, DRAM, and/or other types of RAM), flash memory, secure digital (SD) memory, registers, compact discs (CD), digital versatile discs (DVD), and/or other types of non-transitory computer-readable mediums. Depending on the particular embodiment, these non-transitory computer-readable mediums may reside within the downhole access tool 120 and/or external to the downhole access tool 120. The one or more memory modules 206 may be configured to store one or more pieces of logic to selectively operate the sliding sleeve actuator 146 and the deflector actuator 154. In some embodiments, the one or more memory modules 206 may be configured to store one or more pieces of logic to selectively operate the downhole access tool 120.

Embodiments of the present disclosure include logic stored on the one or more memory modules 206 that includes machine-readable instructions and/or an algorithm written in any programming language of any generation (e.g., 1GL, 2GL, 3GL, 4GL, and/or 5GL) such as, machine language that may be directly executed by the one or more processors 204, assembly language, obstacle-oriented programming (OOP), scripting languages, microcode, etc., that may be compiled or assembled into machine readable instructions and stored on a machine readable medium. Similarly, the logic and/or algorithm may be written in a hardware description language (HDL), such as logic implemented via either a field-programmable gate array (FPGA) configuration or an application-specific integrated circuit (ASIC), and their equivalents.

Accordingly, the logic may be implemented in any conventional computer programming language, as pre-programmed hardware elements, and/or as a combination of hardware and software components. The processor 204 may execute the computer-readable executable instructions, causing the ECU 200 to automatically cause the downhole access tool to automatically, for example, receive a divert signal indicative of transitioning the downhole access tool 120 into the diversion state. In response to the ECU 200 receiving the divert signal, the ECU 200 may transition the sliding sleeve 140 to the open position to allow access to the opening 134 in the tool body 122. The ECU 200 may further operate the deflector actuator 154 to transition the deflector plate 152 into the deflection position. The ECU 200 may receive a passthrough signal indicative of transitioning the downhole access tool 120 into the passthrough state. In response to the ECU 200 receiving the passthrough signal, the ECU 200 may transition the sliding sleeve 140 to the closed position to restrict access to the opening 134 in the tool body 122. Further, the ECU 200 may operate the deflector actuator 154 to transition the deflector plate 152 into the passthrough position.

The ECU 200 may be communicatively coupled to an input 208 that provides the divert signal and the passthrough signal to the ECU 200. The input 208 may be a user input device, such as a computer, touch screen, push buttons, etc. The user input device may be capable of receiving an input signal from a user indicative of transitioning the downhole access tool 120 from the passthrough state to the diversion state. Upon receiving the input signal from the user input device, the input 208 may provide the divert signal corresponding to the diversion state, or the passthrough signal corresponding to the passthrough state to the ECU 200, and transitioning the downhole access tool 120 between the diversion state and the passthrough state accordingly.

Referring to FIG. 6 , a method 400 for treating a hydrocarbon-bearing subterranean formation 104 is described. One or more of the steps of the following method may be performed by the ECU 200 communicatively coupled to the downhole access tool 120. The downhole access tool 120 may initially be in the passthrough state. When the downhole access tool 120 is in the passthrough state, the sliding sleeve 140 may extend over the deflector device 150, such that the outer sleeve surface 142 of the sliding sleeve 140 restricts movement of the deflector plate 152 from the passthrough position to the deflection position. At step S100 of the method, the method 400 may include installing the downhole access tool 120 within the wellbore 100. The downhole access tool 120 may have any of the features previously described in the present disclosure. The downhole access tool 120 may be installed in the wellbore 100 by positioning the downhole access tool 120 adjacent the lateral branch 112 at a junction of the lateral branch 112 with the wellbore 100, and orienting the downhole access tool 120 such that the opening 134 of the tool body 122 is in fluid communication with the lateral branch 112. The downhole access tool 120 may be oriented relative to the lateral branch 112 by rotating the downhole access tool 120. The opening 134 of the tool body 122 may be aligned with the lateral branch 112 so that the radial line 133 passing outward from the center axis 158 of the downhole access tool 120 through a centerpoint of the opening 134 of the tool body 122 is spaced apart from a centerpoint of an inlet 105 of the lateral branch 112 by a distance that is less than 30% of a diameter of the opening 134 in the tool body 122. The downhole access tool 120 may then be fixedly coupled to the wellbore 100 by activating the wellbore anchor 132 to couple the downhole access tool 120 to the casing 114.

At step S110, the method 400 may include transitioning the downhole access tool 120 from the passthrough state to the diversion state. Transitioning the downhole access tool 120 from the passthrough state to the diversion state may include transitioning the sliding sleeve 140 from the closed position to the open position and transitioning the deflector plate 152 from the passthrough position to the deflection position. In embodiments, transitioning the downhole access tool 120 to the diversion state may include increasing the pressure in the hydraulic control line 180, thereby actuating the sliding sleeve actuator 146, transitioning the sliding sleeve 140 of the downhole access tool 120 from the closed position to the open position. Further, the increased pressure in the hydraulic control line 180 may actuate the deflector actuator 154, transitioning the deflector plate 152 from the passthrough position to the deflection position, where the deflector plate 152 may intersect the center axis 158. At step S120, the method 400 may include extending coiled tubing 190 or other wellbore tooling downhole along the central bore 110 to the downhole access tool 120, once the sliding sleeve 140 is in the open position and the deflector device 150 is in the deflection position. When the coiled tubing 190 or other wellbore tooling contacts the deflector plate 152, the coiled tubing 190 is deflected toward the opening 134, and extends through the opening 134 and into the lateral branch 112.

In embodiments, at step S130, the method 400 may include injecting a treatment fluid from the coiled tubing 190 into the subterranean formation 104 in fluid communication with the lateral branch 112. The treatment fluid may include an acid composition. Treating the subterranean formation 104 may include an acid treatment of the subterranean formation 104 in fluid communication with the lateral branch 112. At step S140, once acid treatment of the subterranean formation 104 is complete, the method 400 may include ceasing injection of the treatment fluid. The acid treatment may be determined to be complete based on a predetermined time period, a predetermined amount of treatment fluid, or the like. At step S150, the method 400 may include removing the coiled tubing 190 from the lateral branch 112. At step S160, the method 400 may include transitioning the downhole access tool 120 from the diversion state to the passthrough state. Transitioning the downhole access tool 120 from the diversion state back to the passthrough state may include transitioning the deflector plate 152 from the deflection position to the passthrough position and transitioning the sliding sleeve 140 from the open position back to the closed position. In embodiments, transitioning the downhole access tool 120 to the passthrough state may include decreasing the pressure in the hydraulic control line 180, thereby transitioning the deflector plate 152 from the deflection position to the passthrough position, and transitioning the sliding sleeve 140 from the open position to the closed position.

A first aspect of the present disclosure is directed to a downhole access tool for providing access to a lateral branch of a wellbore. The downhole access tool includes a tool body including a cylindrical wall having an opening extending radially through the cylindrical wall, a sliding sleeve disposed within the tool body, and a deflector device. The deflector device comprises a deflector plate coupled to the tool body, the sliding sleeve, or both and a deflector actuator operatively coupled to the deflector plate. The sliding sleeve, the tool body, or both define a central conduit extending axially through the downhole access tool. The sliding sleeve may be slidable relative to the tool body in an axial direction between a closed position and an open position. In the closed position, the sliding sleeve may restrict access through the opening in the tool body, and in the open position, the sliding sleeve may permit access through the opening in the tool body. The deflector actuator is operable to transition the deflector plate between a deflection position and a passthrough position. In the deflection position, the deflector plate may restrict access axially through the central conduit and nay deflect tooling radially outward towards the opening in the tool body. In the passthrough position, the deflector plate may allow access axially through the central conduit.

A second aspect of the present disclosure may include the first aspect where, in the deflection position, a deflecting surface of the deflector plate may intersect a center axis of the downhole access tool and may form an angle greater than zero with the center axis. In the passthrough position, the deflecting surface of the deflector plate does not intersect the center axis.

A third aspect of the present disclosure may include either one of the first or second aspects, where, in the passthrough position, the deflecting surface of the deflector plate may be parallel to the center axis of the downhole access tool.

A fourth aspect of the present disclosure may include any one of the first through third aspects, where, in the passthrough position, the sliding sleeve may restrict movement of the deflector plate from the passthrough position to the deflection position.

A fifth aspect of the present disclosure may include any one of the first through fourth aspects, further comprising a sliding sleeve actuator operatively coupled to the sliding sleeve, the sliding sleeve actuator operable to translate the sliding sleeve axially between the open position and the closed position.

A sixth aspect of the present disclosure may include the fifth aspect, further comprising a hydraulic control line operatively coupled to at least one of the sliding sleeve actuator and the deflector actuator. The hydraulic control line may be operable to actuate at least one of the sliding sleeve actuator and the deflector actuator.

A seventh aspect of the present disclosure may include the sixth aspect, where an increase in a pressure in the hydraulic control line may actuate both the sliding sleeve actuator and the deflector actuator, moving the sliding sleeve to the open position and the deflector plate to the deflection position.

An eighth aspect of the present disclosure may include any one of the first through seventh aspects, where the deflector plate may be coupled to the tool body or the sliding sleeve at a pivot point, and the deflector actuator may be operable to rotate the deflector plate about the pivot point to translate the deflector plate between the deflection position and the passthrough position.

A ninth aspect of the present disclosure may include any one of the first through eighth aspects, where the deflector plate may be pivotally coupled to the cylindrical wall, and the cylindrical wall may comprise a recess formed therein. The deflector plate may be positioned within the recess when in the passthrough position.

A tenth aspect of the present disclosure may include the ninth aspect, where the sliding sleeve may extend over the deflector plate, such that an outer surface of the sliding sleeve may restrict movement of the deflector plate from the passthrough position to the deflection position.

An eleventh aspect of the present disclosure may include any one of the first through eighth aspects, where the deflector plate may be pivotally coupled to the sliding sleeve, and the sliding sleeve may comprise a recess formed therein. The deflector plate may be positioned within the recess when in the passthrough position.

A twelfth aspect of the present disclosure may include any one of the first through eleventh aspects, further comprising a processor communicatively coupled to the deflector actuator, a memory module communicatively coupled to the processor, and computer-readable executable instructions that, when executed by the processor, may cause the downhole access tool to automatically receive a divert signal indicative of transitioning the downhole access tool into a diversion state, transition the sliding sleeve to the open position to provide access to the opening in the tool body, and operate the deflector actuator to transition the deflector plate into the deflection position.

A thirteenth aspect of the present disclosure may include the twelfth aspect, further comprising computer-readable executable instructions that, when executed by the processor, may cause the downhole access tool to automatically receive a passthrough signal indicative of transitioning the downhole access tool into a passthrough state, transition the sliding sleeve to the closed position to restrict access to the opening in the tool body, and operate the deflector actuator to transition the deflector plate into the passthrough position.

A fourteenth aspect of the present disclosure may include any one of the first through thirteenth aspects, further comprising a biasing mechanism that biases the sliding sleeve from one of the closed position and the open position to the other of the closed position and the open position.

A fifteenth aspect of the present disclosure may include the fourteenth aspect, where the cylindrical wall may comprise a tab extending radially inward from the cylindrical wall, and the biasing mechanism may comprise a spring piston in contact with the sliding sleeve and the tab of the cylindrical wall.

A sixteenth aspect of the present disclosure is directed to a method for treating a subterranean formation. The method may comprise installing the downhole access tool of the any one of the first through fifteenth aspects in a wellbore at a junction of a lateral branch with the wellbore. The downhole access tool may be oriented in the wellbore so that the opening in the tool body is aligned with the lateral branch. The method may further include transitioning the downhole access tool to a diversion state where the sliding sleeve is in the open position and the deflector plate is in the deflection position. The method may further include inserting a coiled tubing into the wellbore, where the deflector plate of the deflector device may deflect the coiled tubing radially outward through the opening in the tool body and into the lateral branch. The method may further include injecting a treatment fluid from the coiled tubing into the subterranean formation in fluid communication with the lateral branch.

A seventeenth aspect of the present disclosure may include the sixteenth aspect, further comprising ceasing injection of the treatment fluid, removing the coiled tubing from the lateral branch, and transitioning the downhole access tool to a passthrough state where the deflector plate is in the passthrough position and the sliding sleeve is in the closed position.

An eighteenth aspect of the present disclosure may include either one of the sixteenth or seventeenth aspects, where the treatment fluid may comprise an acid composition and treating the subterranean formation may comprise an acid treatment of the subterranean formation in fluid communication with the lateral branch.

A nineteenth aspect of the present disclosure may include any one of the sixteenth through eighteenth aspects, where the opening of the tool body may be aligned with the lateral branch so that a radial line passing outward from a center axis of the downhole access tool through a centerpoint of the opening of the tool body is spaced apart from a centerpoint of an inlet of the lateral branch by a distance that is less than 30% of a diameter of the opening in the tool body.

It is noted that one or more of the following claims utilize the terms “where,” “wherein,” or “in which” as transitional phrases. For the purposes of defining the present technology, it is noted that these terms are introduced in the claims as an open-ended transitional phrase that are used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.”

Having described the subject matter of the present disclosure in detail and by reference to specific embodiments, it is noted that the various details described in this disclosure should not be taken to imply that these details relate to elements that are essential components of the various embodiments described in this disclosure, even in cases where a particular element is illustrated in each of the drawings that accompany the present description. Rather, the claims appended hereto should be taken as the sole representation of the breadth of the present disclosure and the corresponding scope of the various embodiments described in this disclosure. Further, it will be apparent that modifications and variations are possible without departing from the scope of the appended claims. 

1. A downhole access tool for providing access to a lateral branch of a wellbore, the downhole access tool comprising: a tool body comprising a cylindrical wall having an opening extending radially through the cylindrical wall; a sliding sleeve disposed within the tool body; and a deflector device comprising a deflector plate coupled to the tool body, the sliding sleeve, or both and a deflector actuator operatively coupled to the deflector plate, where: the sliding sleeve, the tool body, or both define a central conduit extending axially through the downhole access tool; the sliding sleeve is slidable relative to the tool body in an axial direction between a closed position and an open position; in the closed position, the sliding sleeve restricts access through the opening in the tool body and, in the open position, the sliding sleeve permits access through the opening in the tool body; the deflector plate is curved, such that a deflector surface of the deflector plate mirrors a contour of the cylindrical wall; the deflector actuator is operable to transition the deflector plate between a deflection position and a passthrough position; in the deflection position, the deflector plate restricts access axially through the central conduit and deflects tooling radially outward towards the opening in the tool body and, in the passthrough position, the deflector plate allows access axially through the central conduit.
 2. The downhole access tool of claim 1, where: in the deflection position, a deflecting surface of the deflector plate intersects a center axis of the downhole access tool and forms an angle greater than zero with the center axis; and in the passthrough position, the deflecting surface of the deflector plate does not intersect the center axis.
 3. The downhole access tool of claim 2, where, in the passthrough position, the deflecting surface of the deflector plate is parallel to the center axis of the downhole access tool.
 4. The downhole access tool of claim 1, where, in the passthrough position, the sliding sleeve restricts movement of the deflector plate from the passthrough position to the deflection position.
 5. The downhole access tool of claim 1, further comprising a sliding sleeve actuator operatively coupled to the sliding sleeve, the sliding sleeve actuator operable to translate the sliding sleeve axially between the open position and the closed position.
 6. The downhole access tool of claim 5, further comprising: a hydraulic control line operatively coupled to at least one of the sliding sleeve actuator and the deflector actuator, where the hydraulic control line is operable to actuate at least one of the sliding sleeve actuator and the deflector actuator.
 7. The downhole access tool of claim 6, where an increase in a pressure in the hydraulic control line actuates both the sliding sleeve actuator and the deflector actuator, moving the sliding sleeve to the open position and the deflector plate to the deflection position.
 8. The downhole access tool of claim 1, where the deflector plate is coupled to the tool body or the sliding sleeve at a pivot point and the deflector actuator is operable to rotate the deflector plate about the pivot point to translate the deflector plate between the deflection position and the passthrough position.
 9. The downhole access tool of claim 1, where: the deflector plate is pivotally coupled to the cylindrical wall; the cylindrical wall comprises a recess formed therein; and the deflector plate is positioned within the recess when in the passthrough position.
 10. The downhole access tool of claim 9, where the sliding sleeve extends over the deflector plate, such that an outer surface of the sliding sleeve restricts movement of the deflector plate from the passthrough position to the deflection position.
 11. (canceled)
 12. The downhole access tool of claim 1, further comprising a processor communicatively coupled to the deflector actuator, a memory module communicatively coupled to the processor, and computer-readable executable instructions that, when executed by the processor, cause the downhole access tool to automatically: receive a divert signal indicative of transitioning the downhole access tool into a diversion state; transition the sliding sleeve to the open position to provide access to the opening in the tool body; and operate the deflector actuator to transition the deflector plate into the deflection position.
 13. The downhole access tool of claim 12, further comprising computer-readable executable instructions that, when executed by the processor, cause the downhole access tool to automatically: receive a passthrough signal indicative of transitioning the downhole access tool into a passthrough state; transition the sliding sleeve to the closed position to restrict access to the opening in the tool body; and operate the deflector actuator to transition the deflector plate into the passthrough position.
 14. The downhole access tool of claim 1, further comprising a biasing mechanism that biases the sliding sleeve from one of the closed position and the open position to the other of the closed position and the open position.
 15. The downhole access tool of claim 14, where: the cylindrical wall comprises a tab extending radially inward from the cylindrical wall; and the biasing mechanism comprises a spring in contact with the sliding sleeve and the tab of the cylindrical wall.
 16. A method for treating a subterranean formation, the method comprising: installing the downhole access tool of claim 1 in a wellbore at a junction of a lateral branch with the wellbore, where the downhole access tool is oriented in the wellbore so that the opening in the tool body is aligned with the lateral branch; transitioning the downhole access tool to a diversion state where the sliding sleeve is in the open position and the deflector plate is in the deflection position; inserting a coiled tubing into the wellbore, where the deflector plate of the deflector device deflects the coiled tubing radially outward through the opening in the tool body and into the lateral branch; and injecting a treatment fluid from the coiled tubing into the subterranean formation in fluid communication with the lateral branch.
 17. The method of claim 16, further comprising: ceasing injection of the treatment fluid; removing the coiled tubing from the lateral branch; and transitioning the downhole access tool to a passthrough state where the deflector plate is in the passthrough position and the sliding sleeve is in the closed position.
 18. The method of claim 16, where the treatment fluid comprises an acid composition and treating the subterranean formation comprises an acid treatment of the subterranean formation in fluid communication with the lateral branch.
 19. The method of claim 16, where the opening of the tool body is aligned with the lateral branch so that a radial line passing outward from a center axis of the downhole access tool through a centerpoint of the opening of the tool body is spaced apart from a centerpoint of an inlet of the lateral branch by a distance that is less than 30% of a diameter of the opening in the tool body. 